i have a 2.5 4 cly with a 4 inch susp. lift and running 33's. What i am trying to do is get better air flow because i plan on going to 35's soon. I have already added a banks header and a flow mater, And i plan on added a proformance chip here soon. But air flow is where im stuck. I have'nt any epxeriance with anything other stock air box and filter. So any suggestions would be a great help.
Just a snorkle wouldn't potentially improve your air flow over stock as it utilizes the stock system - however a performance aftermarket system such as AEM brute force will. A snorkle would however provide the coolest air out of most any cold air intake system, and might have somewhat of a ram air effect at speeds. Snorkles cannot be used on most aftermarket system - unless you buy an air canister (basically a large can that clamps over the aftermarket intake tube, slips over the filter, then closes again to match the intake tube size coming from the snorkle. These are pricy however, and somewhat hard to find - and may not fit on all aftermarket systems.
Wether or not your engine actually uses enough air to choke up the stock system depends - with a header, free flow exhaust, and some reprogramming you potentially might; but remember that an engine will only use as much air as it needs.
With that said - if you want to potentially have a more free-flowing intake; don't only install an intake system, but be sure to swap out your throttle body for a 4.0 6 cylinder unit (better yet a performance aftermarket bored out unit). It bolts right over and has a larger bore compared to the 2.5L - meaning it can flow more air should you need it.
Which 'chip' are you planning on going? If it's a piggyback unit that sandwiches between some connectors on the computer - they hardly ever do any more good than they do bad. You're better off buying an adjustable MAF sensor, and an adjustable CPS sensor to allow you to change your fueling curves and engine timing; and it'll cost you a fraction of a chip. Chips like the JET systems actually do what these adjustable sensors do - but they're fixed at a certain setting, and can't be tailored to match your system. You can get them (adj. sensors) out of major 4wd Jeep stores like 4wd.com and quadratec.com
also: Keep in mind that the #1 A+ super duper only way to get a significant ammount of your driveability in regards to engine speeds and acceleration back after switching to larger tires (like 33"s or 35"s) is to regear your axles! For 33"s on the 4cyl you'll want to run 4.88's which are available for both the Dana 30 and 35c that come stock in your 2.5L TJ; for 35"s - you'll want 5.13s (however these won't fit in the stock axles - which are a good idea to upgrade anyways, at least in the rear.). These gears would bring your RPM to true speed ratio back to near stock (4.10's on 28" tires)
http://www.quadratec.com/products/pr...+Products&pg=1 ( stage 1 ) thats the link the the chip was i looking at. What is an adjustable MAF sensor? I have never heard of that? Where can i get one and how much do they run? What kind of axels should i run with 5.13's? I have a buddy who has some 1/2 ton 4x4 axels that i can get for cheap. So do you think going with a cold air intake will be a better way to go? Also i want to thank you for replying so fast. Your really helpfull to i never thought about 5.13 gears i was just going to try 4.88 gears. If was did swap out my throttle body to a 4.0 would i need to change anything else?
Hey Wes, that is great advise you have gotten. Out at 360 yesterday, we had to rescue a YJ that had climbed up a pretty steep hill, lots of rocks, and he completely twisted his rear driver side axle shaft in two. We lifted the rear of his Jeep, and pulled the axle right out, tire and all. The D35c axle is crap. They have a whole website dedicated to its weakness, pictures and all. If you can get another rear axle, you will be ahead of the game. You can probably get away with it for a while, especially if you stay on the street. Ken still has his D35c in the rear of his YJ, and is running lockers, and 35" tires. A lot of it is the way you wheel too. He is a firm believer in slow and easy. That is probably why he has gotten away with it for so long. He is also geared low, and has that Deep V Klune that gets his crawl ratio way down there. I also have to agree that the throttle body spacer from a 4.0 will help you much more than a chip. Those are snake oil remedies on a gas engine. That and a less constrictive exhaust system, like Flowmaster, or the like.
my bad, I meant MAP - MAF = mass air flow sensor, MAP = manifold absolute pressure sensor (maf being used on higher end engines - it's currently the most accurate way of measuring ambient air density in the automotive world).
The MAP sensor is the little black box on the driver's side of the throttle body - it measures the air pressure inside the manifold, and sends this reading to the computer. The computer then looks at the IAT (intake air temperature sensor) and crosses the two in a pre-programmed chart it has in its memory to determine an estimate of the atmospheric density, to determine how much fuel to put into the engine to keep close to it's predesignated oxygen to fuel ratio of 14.7:1.
When you swap in a 4.0 throttle body you shouldn't have to change anything. Just carefully remove the stock sensors, and swap them over (or perhaps depending in mileage it might just be a good idea to replace all of them anyways)
I've never heard of anyone having any luck with the chips you're looking at - in fact in some (rare) cases the computer can be damaged permanently by them; hold on to your money and spend it on something else.
What kind of axles does your buddy have? If you swap in Dana 44's front and rear - you can go down to 5.13s, or even 5.38's with them. You can look into axles from a Jeep Wrangler Rubicon as well - these use a Dana 44 for the rear, and a Dana 44 center section (differential) with Dana 30 outers up front. These would bold right up to your Jeep, beef up your axles in the rear, give you selectable locking differentials front and rear, keep your existing 5x4.5" bolt pattern on the wheels, are fully compatible with all bolt on suspension upgrades, as well as steering upgrades, and can be had fairly cheap if you're patient. Just keep in mind because of the fact that these axles use a special locker that you have to order gears made for the Rubicon Dana 44's or they won't fit right.